


Our Family Portrait Is A Sex Tape

by procrastinate101



Category: Gravity Falls
Genre: Dipbel, F/M, M/M, Stancest - Freeform, aged up and down characters, all fuzzy inside like a duckling full of tarantulas, and some smut, let me just ruin everything you love.., lots of talking, lovey dovey incest, my sincerest apologies, one ticket to hell please, pinecest - Freeform, seriously I'm going to special cartoon hell, stanwich
Language: English
Status: In-Progress
Published: 2018-10-27
Updated: 2018-12-09
Packaged: 2019-08-08 06:55:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 8,831
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16424531
Author URL: https://archiveofourown.org/users/procrastinate101/pseuds/procrastinate101
Summary: A relationship is exposed. Other secrets are revealed. The young twins see no reason not to run with it. Oops I made a pinecest story.





	1. Please Don't Leave Me

**Author's Note:**

> DISHONOR! Dishonor on my bloodline! Dishonor on me! Dishonor on my cow!
> 
> The Stan twins have a little brother Alex who had two kids (Dipper and Mabel) when he was 20. Stanley, Stanford and Alex are the sons of Shermie Pines, son of Filbrick Pines.

For the past two months Dipper and Mabel Pines had been living back with their parents, Alex and Ariel Pines. The two 21 year old's had been kicked out of their rented flat due to massive repairs going on in the building. It had been a slightly longer commute to university for Dipper but the two had loved being back in their childhood home. Mabel had graduated from the university Dipper was still attending and worked from home most days. Sewing clothes and costumes she made online. The only downside of being back with their folks was that they couldn't tease and kiss on a daily basis anymore. They had contented themselves with being wrapped up on the couch together. Sharing constant physical contact. Their feet moving in slow teases under the dining table, turning to kicks to throw off their parents. The world just thought they were really cuddly twins.

What they had was _different._ Siblings weren't meant to get along this well. At least that’s what everyone said. And they were dead on. The two twins had had their first real, passionate kiss when they were 15. They'd waited to get physical though. Neither had wanted to tarnish the other with incest. When they were 17 they'd been at a party. It had ended super early when the guys parents came home and threatened to call the cops. Their own parents had been out that night, taking the time to have a date night since the kids were out. Home alone the two had had a dance party per Mabel's request. She'd felt cheated out of a night of dancing. So they'd danced and sang all through the house till they ended up breathless, giggling and kissing on the stairs. Finally slipping away to their bedroom.

At 18 they had fought a lot. They'd been so scared the world would find out. That their parents would be disgusted and hate them. Neither wanted to hold the other back. Not just in the academic sense. You couldn't marry your twin. You couldn't raise children together. So they had decided to make their relationship open. Both needed the other to be happy, more than they wanted their own happiness. So they encouraged each other to date, to love others. They would talk to each other about their other relationships, sex with others, their crushes. Being open did limit who they dated though. The phrase 'I'm poly and I currently have two partners' tended to put several people off. They had ended up picking the same university. Dipper hadn't even allowed Mabel to discuss her choices with him. If separating was best for their education then that’s what they'd do. But fate and a university with an excellent science and art community and kept them together.

Mabel loved being poly. She didn't know if she would have ever started being poly if it weren't for her secret incestuous relationship. She just loved loving. She loved having different, interesting people in her life. She loved that each of her relationships were completely different. She knew Dipper couldn't be her nesting partner, they could never live openly in America. Mabel liked to think of Dipper as her anchor partner. He was the one she lived with, had been with the longest and would always be with. He grounded her to reality. Whereas her boyfriend Wirt (who was a lot like Dipper) was total nesting material. He wanted kids way down the track and she liked him a lot. She could see herself raising kids with Wirt. 

The other Pines twin wasn't as naturally poly as his sister. He still dated others, he understood why Mabel wanted him to find someone other than her. Because he felt the same way. But no one compared to Mabel. He had recently broken up with his long term boyfriend. He'd been on a couple of dates with another guy back at university, but hadn't seen him over the break. Plus his other girlfriend was currently doing an exchange program in England so other than skype calls he didn't see a lot of her.

University had broken up and their uncles were back from their world voyage. They had invited the younger twins up for the summer. The twins were ecstatic, they loved Gravity Falls, their friends and of course their fathers older brothers. 

The young twins had returned to the shack in the early hours of the morning after a party. Being a bit tipsy they had forgotten the security camera in the dark shop. They hadn't done anything too scandalous. Dipper had slapped Mabel's butt, she had squealed and ran forward only to turn and beckon him suggestively. Then the two had run then up the stairs holding hands.

Stan had re-watched the tape a dozen times before he showed it to Ford. The two siting in grim silence.

. ___ •➲⦉ ___ ╷ꟾꟾꟾꟾꟾ ___ -⌲⌲ ___ ⌲☆ ___ .

The four twins sat sombrely around a dining table. Everything was over. The life they had known was gone. The world would hate them now. Their parents would cry and banish them. But worst of all were the looks in Stan and Ford's eyes. Looks of sadness and regret. Dipper wanted to hold Mabel. She was shaking, her face red and puffy. He needed to be holding her, comforting her. But he couldn't. Not now. Stan and Ford would surely see it as perverse. So the twins sat, separated and afraid. 

Stan had made them sit down, said they'd seen something on the security tape form a couple days ago. That they'd been watching the two of them over the last couple days.

"There's only one conclusion we can make." Ford said with a pained expression.

"We know about you two. But we want to hear your side of things." Stan said, his tone trying to comfort his beloved niece.

Dipper was shocked. That was not the reaction he had feared for all these years. They had.. A chance to prove themselves. To explain their side. Maybe then, maybe Stan and Ford would let them be. Maybe they wouldn't tell their parents or try and separate them. 

So Dipper began the tale of their sweet love story. About the issues they'd had after weirdmageddon. The nightmares, panic attacks, loss of focus, Mabel's fear of bubbles, Dipper's flashbacks of being in alternate realities. And of course how they couldn't talk to their parents, school friends or teachers about it. How they soothed and grounded each other through their breakdowns. Been the only ear for miles that the other could talk to. 

Under the table Dipper's hand leant against Mabel leg in assurance. Her body slowly relaxing at the contact.

The uncles nodded in recollection when Dipper talked out their first romances. How he and Mabel had started dating people from school. Long term relationships that had both ended for the same reasons. Dipper's girlfriend had called the twins 'unhealthily co-dependant'. Their partners had wanted something more. 

The break ups had been taken too well. Mabel had been dramatic sure, but neither twin had experienced those brutal break up emotions. Even though they hadn't understood why at the time.

Finally Mabel broke through Dipper's storytelling "we weren't each other's firsts. Dipper wasn't even my second. We might have been co-dependant back then but we're not now. We're not together cause we were lonely or traumatised!"

"That’s not what I was saying!" Dipper defended aghast at Mabel's interpretation.

"Well it's how it sounds!" Mabel sobbed, burying her head in her hands with a silent heave.

Instantly Dipper was standing next to her, hugging her. Then he had stiffened, his eyes turned to Ford in fear. But his uncles just watched with understanding looks so he relaxed and continued.

"I realised it first. I tried so hard to squash my feelings. I tried so hard. I had dismissed dreams of her but then she started popping into my head when I'd um.." Dipper stopped turning bright red.

"When-he'd-wank." Mabel mumbled through her hands for him.

"Um yes. Erm and I started.. I knew it was wrong.. I hated myself for it.. So whenever.." Dipper face was strained. He couldn't find the words. He'd never told this story before. 

Mabel raised her head. Looking into his eyes. He was trying to bore into the floor with his gaze. "Dipper started hurting himself when he'd think of me. He didn't scar himself that much, he kept it hidden. But then he snagged my antibiotics. The wound on his hip had gotten infected. I ransacked our room when he was out. Thought I'd lost them in the bomb site that was my half of the room. I was in the closet when his parker fell of the coat hanger and rattled. I was furious. He wouldn't tell me why he needed them. Why he hadn't just asked for them. Why he wouldn't go to the doctor. He begged me to just go to the next appointment he'd made me to get more. I had a UTI, so I um, really needed them. Finally I overpowered him. He had this massive crosshatch of scars covered in band-aids under his boxers. He told me.. He said he deserved it. I didn’t understand. I was on top of him, pinning him down. He was a mess. Just begging and pleading.. Finally he told me why he 'deserved' it. That he _wanted_ me. That he was _jealous_ of my boyfriend. That he was sick and despised himself." Mabel gushed out, her mind vivid with the memory. She gripped Dipper's hand tightly. Knowing he wanted to run away. Knowing she couldn't explain everything without him here with her. "I was shocked.. But it clicked. I understood."

A nervous laugh escaped Dipper. Looking at her with bright eyes as he whispered "you.. She said, 'then I guess I deserve it too'."

"Heh yeah." Mabel said with a smile. The two were lost in each other's eyes.

Stan wanted to hug the kids so badly. But he restrained, clearing his throat instead.

Puffy brown eyes snapped up, finding Ford's face stoic and unreadable. Dipper would have preferred anything to that. He could understand rage or disgust. They probably deserved it. Seeing that calculating look instead, it broke his heart.

"Please don't hate us. We try not to love each other. We date other people.. I want Dipper to find someone he can marry. Have kids with. He wants the same for me. We're open. We love others and talk to each other about our other relationships. We're poly. We both need each other, but we also need each other to be looking for something better. Something the world could accept. We want each other to be happy more than we care about ourselves. If Dipper wanted to break up, I'd let him go." Mabel finished, her hand squeezing Dipper's. "And if we don't.." She chuckled, "then we'll move to Australia. Dipper will bleach his hair and go by Tyrone Hirsch. And I'll be Matilda McGowen!" She said with a fist bump to herself.

Dipper smiled at her undying enthusiasm. "But we're careful. Mabes isn't going to end up pregnant." Dipper reasoned, searching for any sign of emotion from his mentor.

"Oh yeah I'm on the pill and I've got the implant thing in my arm.." Mabel looked down, unable to say out loud how much she'd love Dipper's baby. How the world would just assume it looked like her.

Stan blushed slightly, looking at Ford in silent confirmation. 

Ford nodded and cleared his throat "Ah.. Well, I don't get the open relationship stuff, but the reasoning sounds, mature.."

Stan scoffed "really? Mature? How are you two ok with the other seein' others? Don't you get jealous?" He asked bewildered, and maybe a little hurt.

"I guess I did at first.. But it's different. We've always loved each other. And others. And now we do that with romantic love as well." Dipper struggled slightly to explain it. 

Ford nodded and exhaled loudly. "I can tell you that I don't want this life for either of you. The loving each other bit. If you do choose to continue, it will be tough. But.." He said with a smile, pulling up his hand from under the table. In his grasp was a five fingered hand. "It can be done." their hands rested atop the dining table. Ford's hesitant smile peeked out from his mask as he saw Stanley's grin.

Two jaws dropped. 

" **WHAT!** " Dipper cried. "YOU TWO?"

"But you two fight _so_ much!" Mabel exclaimed.

"Yes, we do bicker a lot." Ford said with the thinnest of smiles.

Silence filled the room. Dipper's head was imploding. They weren't alone. AND Stan and Ford weren't going to shout their crimes from the rooftop, they weren't even angry. Mabel's smile was growing uncomfortably wide. Seeing the two men before her, who she'd always thought were unhappy. She saw them in a new light. They weren't loveless old bachelors, but a angsty old married couple. 

"Oh-my-god! Oh-my-god! AHHH!! it happened on the boat didn't it!! Or were you together before that? AHHHHH" Mabel slammed her palms on the table, standing up and leaning over it as far as she could reach. Getting face to face with Stanley.

"Well um, we were together before I was kicked out, many years ago.. And then yes, we rekindled on the Stan'O War II." Stan confessed rubbing the back of his head.

"Why, if you're fine with us being together.. Why did you have us explain ourselves?" Dipper asked, the shock ebbing away to reveal mild hurt.

Ford sighed, "well, we wanted to make sure you too weren't just messing around or something. Unlike us, Mabel, you could get pregnant. And the two of you could have normal futures. I spent 15 years in a different dimension, and Stan sacrificed his best years to bring me back. I'm not saying we settled, but our options to have a family of our own are long gone. Yours aren't. But it seems you already grasp that." 

Coughing nervously Stan rubbed a thumb over his twins hand. "You know Dip, I always thought you were gay." He admitted.

Dipper looked up, turning redder by the second "what made you think that?" He blurted in a breath. He had never introduced the family to his boyfriends. Mainly because he'd already introduced them to a girlfriend and he wasn't ready to tell his parents he was poly. The twins feared their parents wouldn't understand how they were _both_ poly. That they would somehow think the two were copying each other or something.

A slight chortle turned into a cough. Stan shouldn't have said it. He should shut up right now. "Ah, well cause I um.. I always thought you had a crush on my man here ." He confessed with an apologetic look.

Mabel's head snapped up, her eyes twinkling. "Oh he does!" She cried.

Hands shot out to cover the girls mouth "she's joking reall-" Dipper started, his face redder than beetroot before shouting in horror. " _EW MABES!_ " He whined pulling his defiled hand off her mouth. Wiping off her saliva on his shirt.

Pouting Mabel grinned cutely, "oh come on DipDop! It's not like this situation could get weirder! Honesty breaks tension!"

Dipper's eyebrow shot up, still clutching his hand like he'd been wounded. "Oh really?" He squeaked, looking towards Stan. "Mabel makes me roleplay as you!" He shouted out before being knocked off his feet.

A war cry followed Mabel as she tackled Dipper to the ground. Tickling and pinching without mercy. "What's done in a bedroom is private you dweeb!" She protested with horror.

The older twins shared a look as their niece and nephew yelled and kicked on the floor. Clearing his throat Ford said to Stanley, "this is.. unexpected."

Two messy brunette heads popped up from the other side of the table. Glaring daggers at each other between looking nervously at the older twins. 

"Hell yes it's fucking unexpected." Stan said looking at Mabel, "how could _you_ like _me_?"

Ford chuckled softly, "well she does sleep with a pig.." He teased lovingly.

To which the three other Pines' all yelled "HEY!"

Stan crossed his arms and stated tersely, "oh yeah? Well now _you're_ not sleeping with anyone!"

Dipper blushed at the cutest pout he had ever seen cross Ford's face. Whilst Mabel laughed at Stan's burn.

Fingers rubbed a birthmarked forehead as Dipper spoke. "I can't believe you guys are together.. I mean this is just so unlikely!"

Ford nodded, his expression calculating, "hmm yes statistically.."

Groaning at his brothers comment Stan turned back to a still beaming Mabel. "I still can't believe you like _me!_ " he empathised.

Ford looked to his side, resting six fingers on his shoulder. "Babe what's not to like?"

"But we're so old!" Stan exclaimed. This wasn’t about his weight, or thinning hair, or past misdeeds. 

"Your only 47!" Dipper defended a little too quickly.

But it didn't seem reasonable to Stan. "That's six years older than your dad!" He exclaimed.

Ford soothing voice stated, "come on now Lee. I'm sure they are both long over their crushes. Don't embarrass them further."

A chortle spluttered from Mabel "HA! That's a nice thought!" She said whilst her brother buried his head in his hands.

Looking at his blushing nephew Ford's voice broke as he said, "wait, what?"

Unembarrassed Mabel reasoned out her feelings. "Well.. We both have the hots your you guys pretty bad.. I mean we love each other! but.. I don't know. You both make us feel so safe.. Your our dinosaur punching heroes. Your everything we want to be. Everything we love about each other. And now that we know you love each other.. Well that means you two probably understand us more than we understand ourselves. And thinking of you two together.. That's gonna give this guy," she elbowed Dipper beside her. "The greatest dreams he's ever had!"

"AH MABEL!" Dipper yelped as he tackled her to the ground and sat on her. "One more word and I'll do it Mabes!"

"Noo!" Mabel cried, "not the face fart!"

Laughing Stan reassured the young twins. "Don't worry Dipper.. The feelings are all mutual."

A squeak high enough it could have signalled bats came out of Dipper. "Wait what?! You guys like us too? Aren't you gay? And why would you like us? We're so.. Do you.." Dipper's voice got somehow higher and faster as he rambled.

"Easy Dip, breathe now.." Ford said calmingly. "No neither of us are gay. Stan likes everyone and I.. Its more the soul I'm attracted to."

"I take it your bi too then?" Stan asked Dipper, who was still sitting on Mabel.

"Um yea." Dipper affirmed.

The group sat in silence till Mabel couldn't resist. "So you guys aren't open like us.." She caught a warning look from Dipper but continued with a shit eating grin. "But if you like us, and we like you.."

Ford stood abruptly, his face flashing with something too quick to catch. "Absolutely not! I know that we've all clearly crossed the incest line but, well we're your uncles! We changed your fathers nappies! It's not like we're even once removed! I mean maybe if we were your great uncles.." Ford rambled as he unconsciously backed away.

Mabel huffed, pushing Dipper off her and helping him up. "Ford that's ridiculous! We're all twincesting already-"

Stan cut her off with sudden laughter, "twincest? HA I love it!" He nudged Ford cutely, "hear that IQ! We have a label!" 

"Yeah so compared to DipDop here your practically my distant relation!" She reasoned, not seeing the problem.

Ford coughed, but he had to put his foot down. "Look honey its fine to talk about our um, sexual identities. But anything beyond that.. It really would be very wrong for anything else to happen here." He stood behind his chair. Truth was he'd had the stirrings of an erection ever since the beginning when the two young twins had been holding hands, at the dusty blush that was creeping over Dipper's neck. Brilliant insightful Dipper. Memories of that blush appearing before had filled his mind. Back when they'd collaborated on projects.. Had Dipper been thinking about him all those years? Getting nervous and flustered because of him? No. He'd been a monster all these years. His dreams of Dipper underneath him were wrong. He'd been taking advantage of a child in his head. He was a terrible human being.. And yet there they were, the two most gorgeous faces, starring at him with love and hope and _want_.

Mabel was not satisfied. How could they look between her and Dipper and say it was alright for her to love him, but wrong to love them? "You can't hide behind the morally wrong card. If you don't want be with us that's fine, but do it because it's what _you want_ to do. Not because it's what you think you should do."

Stan coughed nervously. "Fords right sweetie. It, it would be wrong. Your not.. Your young! We would be taking advantage."

Finally Dipper spoke up. His voice clear and reasonable. "No." He looked at a clearly uncomfortable Ford. "We love each other. We've been dealing with this for years. Wondering if it's wrong to simply love. It's made us more mature than most our age. Not to mention the things we've seen and done here in the Falls. Ford, you've told me time and time again that I'm mature for my age. Either that was I lie or you really do believe that. So please don't play that card. We're not kids. Like Mabel said, if you're not comfortable with us that's fine. But we've been legal for five years. You wouldn't be taking advantage of either of us, and to say so is disrespectful to both Mabel and I."

Ford's mouth opened and closed. Unable to find the words. Why didn't Dipper see this was terribly _wrong._

Brown eyes sparkled beside his brother. "I love it when you does that. You're a good kid Dipper, sorry _man._ Verbally backing my brother into a corner. Only way I can do it is physically." He said with a teasing wink. "But he's right. We're too old for you."

Dipper blushed, looking away from Ford's dark gaze.

The comment made Mabel laugh however. "HA! You wouldn't even be the oldest guy Dipper's been with!"

Ford's gaze grew darker.

"NOPE no! No, _no MABEL!_ LIMITS exist for a _reason!_ " Dipper cried aghast and embarrassed.

"They're family!" Mabel reasoned with a grin.

Two could play that game. "Oh so I can tell mum about her tennis coach?"

Mabel gasped in horror " _you wouldn't!_ " 

"Try me!" Dipper grinned as she lunged at him and the fell rolling and tickling on the floor again.

Mabel won. Sitting atop Dipper's back triumphantly. She cocked her head to the side as an idea came to her. "Oh my god guys! This is _'pinecest'_. Ha! Get it cushion?" She winked at Dipper.

Ford abruptly grabbed Stan's hand. **"Nope!"** he cried as he pulled Stanley out of the room.

.___ •➲⦉ ___ ╷ꟾꟾꟾꟾꟾ ___.

Ford sighed, leaning against their locked bedroom door.

The original mystery twins spoke in unison, "I can't believe it.."

Ford continued with, "the coincidence!" 

Whilst Stan said, "we're so old! You at least have that grey fox look.."

"Oh Stan, you know how beautiful you are." Ford tried to reassure him.

"Eh, your just bias." Stan waved the compliment off. "You said yourself about the more familiar the face, the less time the brain takes to identify it. We register the speedy identification as beauty. You've just looked in the mirror too much." Stan teased.

Ford sighed. Letting go of his worries that he was a monster for wanting their young relatives. "Oh here we go again." He said with a smile, stepping towards his twin. Kissing Stan's cheeks, his chin, his neck and chest, he pulled his hands up and kissed his hairy knuckles. All whist saying "You. Are. Beautiful."

Later that night Stan rolled over in their bed and sighed "I am worried though. What if she gets pregnant?"

Ford hummed thoughtfully. "I could run some tests. See how many recessive factors they both have. It might deter them."

"I couldn't bear it if they fled to Australia. Could you imagine dipper bleach blonde! What a sight!" Stan confessed.

Ford squeezed his eyes shut in a fleeting moment of despair. "Yes. And I still think they'd look like twins."

"We could convince them this life's not so bad. Or try to push them apart." Stan offered, not sure which was better.

Ford smiled with a sigh. "I know you could never do that. Your all heart Lee."

"Shush cutie." Stan reprimanded. Snuggling up behind his twin. A gasp of horror left Ford when he felt an erection against his back. "Really Stanley? They're so close! What if.. What if we thought of them!"

"Gods sixer, what do you think got me hard?" Stan groaned.

.___ -⌲⌲ ___ ⌲☆ ___ .

Two floors up two 21 year old's sat across each other. Their twin beds pushed up together. They'd never moved them before.. But they no longer had to hide here.

"Oh my god." Mabel breathed.

"I know." Dipper agreed beside her.

"Oh my god." Mabel sighed again.

Dipper groaned, lying down. "Yeah Mabes."

"No, no but Dipper. _Oh my god._ " Mabel reasoned.

The boy face palmed.

When the attic had faded into darkness Mabel's voice broke through the edge of Dipper's sleep. "Were totally gonna seduce them right?"

Dipper sat up aghast, _"Mabel!!!_ "

"What." She whined, "like you weren't thinking it."

"I was **not.** " Dipper defended.

Mabel scoffed. "Oh pish, _please pass me the quantum twisty thing my boy._ " She said in a deep voice.

"Nooo Mabel!" Dipper begged.

" _Oh Dipper lad, you're so brilliant, I'm so proud of you!_ " She continued her impersonation.

Dipper pounced on top of her. "Now is not the time for impressions Mabel." He snarled, his dick already half hard in defiance.

Mabel reached up and kissed Dipper sweetly. "I love you."

Dipper collapsed, melting into her neck. "I know babe. But, if they don’t want-"

"But they do!" She argued.

"Still-" Dipper reasoned, his voice breaking when hips pushed up against his.

"Remember that time with Tom? When I just watched you fuck him?" Mabel teased, rolling her hips over a stiffening cock.

Dipper smiled, "you mean when he fucked you."

"Meh semantics." Mabel dismissed. "I had a great view. But Dipper.. What if Ford-"

Dipper silenced her with a kiss. "We have to respect them. _Mabel,_ swear you won't do anything.. _Untoward."_

She grinned up at her lover. A pained, restrained expression on his face. "Hmmm I don’t know… I'd have to be _pretty satisfied_ not to-" 

Dipper grinds against her harshly, cutting off her words. He kissed her in the dark as he pulled a leg up. "Fuck Mabes your soaked!" He exclaimed as a hand swept over her underwear.

"Hmm?" Mabel gasped as her clit was rubbed through cotton. "Oh.. I've been thinking about Stan." She admitted with a grin.

Pushing up her other thigh, Dipper hiked up her sullied panties with them. Her knees resting familiarly on his shoulders. With a grunt he lowered his boxers before sinking in. "What was that _sweetie?_ " He said gruffly, making his voice go rough and hoarse.

" _Fuck_ -" Mabel gasped, her body shivering in pleasure as she was suddenly filled.

Dipper moaned as she tightened around him. She was really slick. After a few thrusts her warm and wet stickiness had completely coated his long, thin dick. Excess was starting to glaze his balls. Benefits of being young she always said.

With a particularly hard thrust Mabel moaned loudly, her bundle being pushed back and forth by Dipper's hard head. 

Thoughts of his uncles filled Dipper's head. He could feel Ford's dark gaze on him from before. Mabel's hands were trailing over his chest, lightly flicking his nipples and tangling in the trail of hair above his dick. He let his mind envision they were Ford's fingers. His big, wide fingers; six tips running lovingly over his body. The young man moaned loudly in the dark.

His hand travelled under one of his baggy tees to feel Mabel's perfect little boobs whilst her teeth grazed his neck. 

Determined to contribute Mabel squeezed herself. She had remarkable control over her vagina. She could suck in air and release it if she wanted. Sounded just like a fart. But when Dipper was inside her and she squeezed, well it was harder but so worth it.

He went lax above her, groaning in agonising bliss as her body tightened harshly around his swollen member. With his head buried in her neck he saw stars till she unclenched her muscles with a gasp. Dimly he was aware of little kisses on his cheek. Drawn back to reality when nails dug into his arse. Mabel was wiggling, trying to restart his movement.

Dipper kept one hand under a knee, bending it flush against her whilst he thrusted.

Mabel's hands wove around his neck, pulling him in for kisses.

Her ankles locked together behind his back. Attempting to keep him closer, drive him deeper.

When Dipper's hand squeezed between them to rub at Mabel's clit she soon convulsed around him, gasping in pleasure. Her blood turning to butter for a blissful ride. 

Between her tightening walls and the gorgeous moans she was emitting Dipper came hard. Fully seated within her as his ball constricted before he shot his load out. 

The two breathed in the sweaty air deeply. Dipper bit back a cry, a horrible thought coming to him. "You don’t think they heard us do you?"

"God I hope so." Mabel gasped, still catching her breath.


	2. Alignied in Separation

•➲⦉ . . . ⌲☆

Stanley Pines was headed to the couch, he'd taken to wearing pants over his usual boxers since a recent family revelation. It no longer seemed appropriate to wander the house half dressed. Only the man was stopped dead in his tracks, forgetting his plans to become so entrenched in the couch Ford would need a crowbar to pry him out. On the floor of the living room an arse was propped high and wiggling as its owner reached under the couch. Stan coughed in sudden embarrassment after several long seconds of staring at the provocative display in awe.

There was the faint cuss of 'flaming flamingos!' before Mabel banged her head in a startled reaction. Slowly struggling out from her awkward position Mabel found her dusty self looking up at her uncle's crimson cheeks and everted eyes.

Stan's tense figure spoke. "You okay.. Mabel?" He caught himself from saying love at the last second.

"Heh, yea just clumsy." Mabel admitted with a blush. Shyly looking away she murmured "I was beading.. One of my glass ones rolled under.." She looked towards the mess of wire and beads spilling out from tiny storage boxes that covered the floor. 

It was a warm, muggy day so Mabel was in a purple tank top and denim shorts, it was all.. Very tight. To Stan's credit his gaze didn't trail back down to her milky thighs or the dip of her waist. But he did find his attention drawn to her lips as she spoke, forcing himself to look back at her eyes several times. "You erm, want help looking?"

"Oh no, I'm sure I'll find it before the dust mites take me." Mabel waved off the offer with her hand, desperately trying to pry a smile out of her nervous uncle.

Stan's eyebrows drew together. Should he offer to clean? "Oh okay."

"Um Stan?" The girl said the instant the man had made to turn away.

"Yeah?" He said instantly, shameful hope blooming in his head.

"About.. Yesterday.. I'm really sorry I made you feel uncomfortable. It wasn’t my intention." Mabel apologised. It really was her fault. Her uncles hadn't even come out of the closet yet let alone talk openly about their incestuous crushes. She knew from long talks with Dipper that sharing before you were ready was uncomfortable and hard. And that's what she and her brazen, yet 100% honest, comments had forced her uncles to do. Well, actually they probably would have come out of the closet and revealed their relationship. But she was defiantly responsible for the admissions of the crushes they all shared. And she had a feeling it was the latter that was causing the tension.

"Oh no. _No._ Mabel never. Well I mean maybe but no. You did nothing wrong honey." Stan said quickly, rushing to stand before her. "Just never tell your parents. Or anyone else. In fact text Dipper what you want to say and let him approve it for you." Stan joked with a wink. They had both bonded over having controlling twins before. 

Mabel chuckled and leapt off the ground. Throwing her arms around Stan with a mumbled, "I'm glad," into his chest.

A voice inside Stan's head was yelling. _Think of her as a baby in diapers, think of your grandmother in a bikini, think of the pig!!_ He coughed as he pulled away, visibly flustered. "You want a cuppa tea love?" _Damn it she's not 'love' anymore! That can't happen so don't go giving her ideas ya fat welp!_

"Yes please!" She answered brightly.

After Stan trotted out of the living room the girl released a sigh. Then she bent down and used a spare ruler to bat a very dusty bead out from under the couch. With a triumphant cry and headed to the kitchen herself.

"Gotta wash it ya know." She told her uncle with a happy grin. "Kills the dust mites." Water slid over her hands as she scrubbed her skin.

Stan nodded silently as he poured hot water into two mugs. Instead of having a kettle like a regular kitchen they instead had a geeky, steampunk looking pot. It was actually just their old broken kettle but it had been stripped and modified. Now it collected energy through the water or some shit. All Stan knew was that it was twice as heavy and he wasn't allowed to buy a new one. But it was super-fast and used zero electricity so meh. As long as his brother wasn't summoning demons he could busy himself however he pleased. Or at least, that’s what Stan would tell himself whenever Ford 'fixed' something around the house.

The 21 year old hopped up onto counter like she had a million times before. Leaning back and with her legs spread. "So…" She started as she watched her uncle add milk to her tea, a wicked grin spreading across her face. "Do anything _special_ last night?"

A loud snort was immediately followed by a coughing fit as Stan nearly dropped the milk bottle.

Mabel laughed easily. Regretting she hadn't waited for Stan to be drinking. A spit take would have been so funny. "Oh this is so good! I finally have ammo against you guys!" 

A very red Stan passed her a hot cup of tea before walking to the other side of the kitchen. Probably finding a shred of comfort in the distance between them. "We would never.. With others in the house.."

Guilt flitted over Mabel's face before being replaced with a shit eating grin. " _Never?_ " 

" **Mabel.** " Stan warned gruffly. His partner had been very clear. No sex with their baby brother's babies. But if Mabel pushed it, Stan would probably give in. He needed the wet blanket that was his twin to have any hope of resisting.

"Sorry Stan! It's just such a relief to be able to share this you, you know? Has anyone ever found out about you and Ford before?" Mabel asked with McGucket's face in mind. 

"Oh no. Well I don't think so. We'd probably have been blackmailed and arrested if someone had. Are we the first to know of you and.." Stan trailed off. Damnit he hadn't had this much trouble saying the word sex since he was twelve.

"Hmm I don’t know. We've had a couple threesomes and two foursomes, does that count as someone finding out? I guess-" Mabel was interrupted mid tangent by Stan.

Hot tea had sprayed out of his large nose. Eyes watered as he coughed, his nostrils hot and his lungs heaving.

Mabel continued after a laugh. "Anyway I guess not cause people kinda assume it's our first time together, or that we're just kinky. No one's ever thought that we were in romantic love. I take it that’s not something you and Ford do?" Mabel asked innocently as if she were discussing the weather.

"Mabel, honey, I get that you two aren't exclusive.. But _fourways!_ That’s.. Don’t you.. We've never.. With anyone… Why? I mean it's not like your dating these people so why?" Stan's voice strained itself in confused horror.

Mabel looked to the floor, hunching over with subconscious feelings of rejection. She felt judged. And sure it wasn’t _that_ normal to have foursomes.. But that was hardly the _weirdest_ aspect of her sex life. "Well, we've only done four twice, well, three times if you count morning afters. Most of the time we're just out together and someone will like both of us. It’s really nice to share someone. We tell each other everything anyway, it's nice cause your with someone new _and_ someone you love. Plus it's safe cause we're together, so the stranger is unlikely to be a serial killer."

"So, how often do you do _that_ then?" Stan asked, unable to articulate further.

"Oh I don't know.. Every couple months? It sorta just happens you know? One of Dipper's ex's wanted to try being with a girl.. So Dipper suggested that he asked me if.. Cause I'm like the girl Dipper.. Anyway I acted all shocked and stuff, like I didn't know my twin's boyfriend was about to ask me straight up for sex. Then Dipper came home and.. it turned into a three-way. He is actually bi, he just prefers guys, Dipper's ex that is. Oh then there was this married couple.. They were adorable.. And the other foursome.. It was actually one of Dipper's girlfriends and one of her boyfriends. Bro let slip about this gorgeous blonde guy we did together to her and she.. Well she told her other boyfriend and they asked Dipper if he'd do it again. Which is hilarious. Anyway Dipper acted all shocked but promised to ask me and bam. They weren't as fun as the married couple though. And I'm totally rambling.. _Uncle Stan_ you're meant to stop me! But anyway it doesn't happen to frequently cause well, we're not two guys. I mean you and Ford would have a _way_ easier time to find someone who fancies both of you!" Mabel chugged her overly sweet tea to keep herself from speaking.

Stan was intensely staring at his fingers curled around his mug. His old, hairy fingers that had no place cupping Mabel's face or running down her body. He again found himself picturing grandpa Filbrick in a speedo.

Mabel's nattering voice broke through the silence again. "I guess I assumed, you both seemed so confident. But I guess you guys aren't trying to have an open relationship. Is that why it would be weird? Would you start thinking of Dippy as Fords new boyfriend and get jealous?"

Wide eyes matched the gaping mouth pointed towards the girl. "I.. I don't think… what?" 

She had gone too far. She wasn't meant to mention or insinuate. Dipper had been _very_ clear. Quickly finishing her tea Mabel jumped off the counter. The empty mug clicked down on the counter by the kettle. 

Mabel threw Stan an apologetic smile. Aw hell she thought. In for a penny in for a pound. "Just, god please don't tell Dipper I mentioned this, but please just don’t dismiss the idea?" She smiled sweetly and peeked Stan on the cheek. "Thanks for the cuppa!" She thanked the still gaping man before skipping away. 

Closing the door into the living room behind her she leaned against the wood with a wide, guilty-ass grin. A bead emerged from her pocket as she made her way back to the floor.

╷ꟾꟾꟾꟾꟾ . . . -⌲⌲ 

A small knock floated down the stairs. The old vending machine entrance had long been replaced with a door. "OPEN!" Ford shouted. He often worked with dangerous chemicals and had a rule about Stan barging in, so he was greatly surprised when his nephew can silently down the stairs.

"Um hey Ford.. You said yesterday to pop by.. But after everything.. I can just go." Dipper said nervously. He had already spent 20 minutes standing in the gift shop, plucking up the nerve to come down the stairs.

"No, no my boy come in.. I'd dearly love your company. Don’t ever doubt that." Ford stated, sadness creeping into his voice.

The two watched each other in silence before Dipper pipped up. "I wanted to ask.. Do you regret being with Stan?" He had to know. Ford was so smart, if he considered this life a mistake. Then it probably was.

Ford sighed and put down his current project. "Sometimes. When I see photos of those years I missed. I see him with you two in his arms as babes and I think of the life he could have had. With a partner whose hand he could hold on the street. Who could have given him children. He has Soos though, so in a way he did find that.. But there is a shame that we share. A burden I wish he didn’t have to bare. The funny thing is that he feels the same way. And that neither of us _actually_ want that other life. We just want it for the other."

"I guess I don’t want that other life either.. But sometimes I feel so guilty. I think Mabel would be able to move on, love another if I wasn’t around. I just want her to be happy. I don’t want her to have regrets." Dipper admitted sorrowfully. 

"Dipper, you're not thinking of.." Ford exclaimed horrified. He knew of the guilt, the shame, hating yourself for dragging down the most important person in your life. He often wished Stan had moved on, or had simply failed to re-open the portal.

"Oh no! I just.. Well if there _was_ an accident.. That would be ok." Dipper stated.

Ford walked over to the young genius and embraced him in a tight hug. "I know how you feel. But **your wrong.** We think they're so strong, that they would cope. But just look at how hard Stan worked to try and save me. He learned _physics._ " 

The pad of Ford's thumb wiped a leaked tear from Dipper's red eye.

Pulling out from the hug Dipper forced some perk into his voice. "Ahha so, what did you want to show me?"

 **?** . . .  ICE

Lights and laughter flashed from the slither of basement window onto the lawn. Soos and Wendy were currently setting up a picnic table. The shop wasn't open today. Wendy had long since stopped working at the Shack and Soos was now Mr. Mystery. But today, they were all eating lunch together to catch up with the twins. 

"Dude, did you get like a weird vibe from Stan today?" Soos asked he brushed spiders off the long unused chairs.

"He was a little jumpy.. Maybe he's building another dooms day device?" Wendy pondered with a grin.

"Ha! Maybe.." Soos trailed off in very slow thought.

Wendy smiled fondly as a loud 'it works!' echoed from the basement. "Don't worry mate. He's probs just stoked to have the twins back again."

A car pulled up in the drive way and a colourful girl bounced out. "I have FOOD!" She exclaimed as she set the bags down, before running inside to gather the rest of her family.

The lunch was nice. Everyone laughed and chatted in the spring sunshine. But something was a bit off. In the awkward way bread rolls were passed and the bashful stammers after someone would accidentally interrupt someone else. The 25 year old red head saw what Soos had meant, but couldn't quite put her finger on it.

-⌲⌲ . . . ⌲☆

Late that night Dipper went to bed to find his sister playing on her phone in their bed. 

Pushing her off his side he tried to focus on his book. After reading the same paragraph eleven times he put it down with a huff. "Mabel."

"Yes chicken-wing-thief?" Mabel said without looking away from the bright, flashing colours on her screen.

"If um.. If we were.. How would you hypothetically go about say.. Seducing our uncles?" Dipper asked with a crimson blush spreading across his features.

Instantly Mabel sat bolt upright accessing her twin with a wide grin. " _Hypothetically?_ Wake them up with blow jobs!"

A mortified Dipper hid his groan behind his hands. Tensing in predictable shame. Because of course his twin deemed that acceptable. "Mabel!" He scolded. "That’s molesting without consent, not seduction! Try something that doesn't follow 'charged with rape for-"

She turned away, her smile fading into a mock, hurt expression. "Fine. Won't do it _ever_ again then. Sorry for raping you. Repeatedly."

"What no.. _We're ok,_ we're already together!" Dipper whined as he reached out to hold her shoulder comfortingly.

Smirking Mabel looked back at her lover. "Shesh Dip fine. I guess you _might_ be right anyway. Hmmm, well we know Stan watches the security tapes.. So what if we gave them a proper show?"

"MABEL!" Dipper yelped before clamping his hand over his mouth and looking at the door in fright. He continued in a low hiss after a pause. "We are _not_ making a sex tape!!"

A dismissive hand waved away her brother's indignation. "Oh please like they'd ever do anything with it. Well nothing _we'd_ 'disapprove' of at least." Mabel teased with a cheeky grin. 

"Nope. Next idea." Dipper stated firmly.

There was a scowl and a pondering pause before Mabel spoke up again. "Okay, okay. This one's good. We wait till they're just about to go to bed, beat them to their room so that when they open the door we're naked and sexin' it up on their bed!" Mabel revealed with a grin.

"What! _How_ is that better?" Dipper didn't know how they were related.

"Well it's better cause then they see it but there's no evidence!" Mabel reasoned passionately.

Dipper smiled at his sisters expressions. "I don’t think so.. I think Ford would just slam the door on us after a second."

"Hmm maybe." Mabel half agreed. "So _seduce_ them eh? That’s what you want?" She was caving. If Dipper didn't want to bulldoze their way into this then she'd listen. "Well we could get down to the basics. What do you reckon they're into?" Mabel didn't wait for his reply. "How about you in a school girl uniform and me dressed as a dominatrix! And then we just go about our day!" 

A shocked, baffled silence met Mabel's proud grin. Finally Dipper managed, "what! _Why?_ **No.** "

"Why not?" Mabel asked with a cheeky pout.

Dipper didn't want to dignify that with a response. "Fine how about you as a playboy bunny and me in a suit." Sexy. Sexy could work. Maybe..

"Really?" Mabel asked in surprise. "One, my bunny's at home and two I really think we need to play to our strengths. So maybe both of us as cheerleaders?"

"Why do you want me in a skirt you heathen!" Dipper asked in a hushed, hurt fury.

Understanding flitted through Mabel. "Fine, fine me as a cheerleader and you as.. A boy scout or something."

"Mabes," Dipper groaned, leaning back against the wall. "We should be making ourselves seem older! Otherwise they'll get all guilty!"

Mabel pondered this for a minute before speaking slowly but surely. "I disagree. They like _us._ What we are. And what we are _is young._ We want to hit them with such raging hard-on's they can't form coherent speech! _Ohhh!_ You naked under a lab coat!"

Dipper's eyes lit up with mischief. "I actually like that one. But, give them a little credit. _Most people_ have restraint." 

A light punch met his arm from a smiling twin.

"Fine then. No nudity, no sex, no costumes. This is why _I'm_ the fun one. How about a good old romantic dinner then. Wine, candles, home cooked food, no underwear... How's that sound Mr Prude?" Mabel asked, desperate to get Dipper to agree to _something_.

"Too obvious. Plus if it involves your cooking.. Well we're trying to persuade not poison." Dipper teased.

Mabel's hands flew up in exasperation. "Oi! I make delicious food!" 

"Remember Wirt last valentines?" Dipper prompted.

"That's cause he didn't feel like seafood that day!" Mabel defended.

Dipper's head shook off his grin. "No it's cause he didn't want salmon in a chocolate gravy but didn’t want to offend you cause he still wanted in your pants. And do I even have to mention your glitter chicken?" He said as if it would instantly win the argument.

" _How dare you!_ You love that!" Mabel exclaimed with shock.

"Yes, after years and _years_ of building up a sugar tolerance." Dipper argued, then pulled out his high card. "But okay then. What about _Toby's tooth?_ "

"That wasn't on me! Dinosaurs are very clearly _decoration only!_ " Mabel cried out as she leapt onto her knees. "Orange dinosaurs are clearly made of plastic and **not** carved carrot!"

"Yeah, but Mabes, most people use dill or pansies! Look I love your meals.. but sexy isn't the adjective I think of when I think of your chips salad." Dipper reasoned in a soothing voice.

"I stand by my salads. Chips and that great crunch _and_ salt. Win win! Just you wait! One day chips garnish will be as standard as croutons! Just like my old tea-hot chocolates!" Mabel practically whined as she sat back on the bed. Hunched over because this whole conversation felt like an attack on her ideas.

Dipper let out a long sigh and when he met his twins eyes again, it was with a reassuring smile. "Okay if **we** cook a 'romantic' dinner.. How would it be different from every other dinner we've had with them?"

"Well. We could serve it in see-through aprons." Mabel suggested in her cheesy grin.

"Ha. Stan would love that. But all of these ideas.. They would just run away.. Maybe if we could trap them.." Dipper mused.

"Oh Dip that's brilliant! We could do it in the basement! No exits! We could rig the door to like, break after its next use.. And we're already down there.. Naked and gettin' it on, or dressed up.. Or both! They won't stand a chance against our sexiness!" 

Dipper listened with a smile before he prepared to reason with the ball of energy beside him. "That door is solid steel Mabes. We really would be trapped down there. It has to be somewhere else."

"With you two Brainiac's? Please. We'd be out in an hour." Mabel dismissed confidently.

"Then why trap them?" Dipper asked in confusion. Imagining a red-faced Ford shielding his eyes and telling Dipper to help him fix the door. When Ford told him to do something.. It was weird. He felt all fluttery and would eagerly do it. Patiently waiting for a slip of praise.

"Cause then they'd _have_ to watch us doing it! No escape! And then they'd join in!" A happy voice exclaimed.

"But.. Ford would know it was me.. He'd be so disappointed…" Dipper heated in shame at the very thought of Ford's disapproval.

"Nahhh." Mabel waved off his worries. "He won't be doing much thinking. And after he'll just be glad he caved. Might even think your inventive and bold."

"I really, I don’t know about this Mabes." Dipper said hesitantly, worries creeping in on him.

"Okay. Well we'll keep thinking alright? Who knows. They might be about to cave anyway." Mabel soothed.

"Maybe. But I don’t think so. Ford's too…" _Dignified, in-control, mature, resolute…_ Dipper trailed off in thought.

"You underestimate your hotness bro. But we'll sleep on it." Mabel reached over to where Dipper was leaning against the wall and pulled his top lip into a kiss. 

It was a slow, assuring kiss. The two tasted each other's minty fresh lips before Mabel pulled away with a loving smile. Then she crept under the covers on her bed, one foot still stretched out onto Dipper's side.

Dipper tried to pick up his book again, but his mind didn’t want to read. It kept straying to Ford's disappointed frown. After five minutes of failing to regain interest in his book he sighed and turned the light off. Letting Mabel's legs entwine with his.

**Author's Note:**

> I'm a big fan of the sibling relationship shown on this show. It's Disney's best one since Lilo and stitch in my opinion. And I love plutonic relationships. TV needs more of them. It was so great to have siblings not fighting and bickering and just be there for each other. 
> 
> When I first saw this ship I was horrified that something so pure and healthy could be warped like this. 
> 
> But here I am writing a fic for them. Younger me would kill me then disown my burning corpse.


End file.
